1. Field of the Invention
The present invention relates to a rotary electric machine such as an automotive alternator, and particularly relates to a mounting construction for a stator winding that is wound into a wave winding in a stator core in which slots are formed at a ratio of two slots per phase per pole.
2. Description of the Related Art
In conventional rotary electric machines, a stator winding is configured by wye-connecting a U-phase winding, a V-phase winding, and a W-phase winding in each of which a first winding and a second winding that have a phase difference of 30 electrical degrees from each other are connected in series, and the first winding and the second winding are each configured by connecting a plurality of windings in parallel (see Patent Literature 1, for example).
Patent Literature 1: Japanese Patent Laid-Open No. 2010-136459 (Gazette: FIG. 15)
In conventional rotary electric machines according to Patent Literature 1, because the plurality of windings that constitute the first winding and the second winding are concentrated windings, turn counts of the windings can be changed easily. Thus, problems with cyclic currents in parallel circuit portions can easily be solved by making the turn counts of the plurality of windings that are connected in parallel equal. In order to achieve desired output characteristics, the turn count between the first winding and the second winding that are connected in series must also be changed, but that requirement can be met easily by changing the turn counts of the windings that constitute the first winding and the turn counts of the windings that constitute the second winding.
Even if the plurality of windings that constitute the first winding and the second winding are constituted by wave windings instead of concentrated windings, problems with the generation of cyclic currents in the parallel circuit portions can be solved by making the turn counts of the plurality of windings that are connected in parallel equal, and predetermined output characteristics can be achieved by changing the turn counts between the first winding and the second winding that are connected in series.
Now, let us assume that the first winding is configured by connecting two four-turn wave windings in parallel, and the second winding is configured by connecting two three-turn wave windings in parallel. In that case, eight conductor wires are housed in each of the slots in which the first winding is mounted, and six conductor wires are housed in each of the slots in which the second winding is mounted. Thus, the number of conductor wires that are housed in the slots is different in each slot, and one disadvantage has been that unevenness occurs on the inner circumferential surfaces of the coil end groups of the stator winding, generating loud wind-splitting noise with the rotor.